Iosif Stalin IS-2
Origns: The KV-1 was criticized by its crews for its poor mobility and lack of a gun heavier than the T-34 medium tank. It was much more expensive than the T-34, without having greater combat performance. Moscow ordered some KV-1 assembly lines to shift to T-34 production, which led to fears that KV-1 production would be halted and the SKB-2 design bureau led by Kotin closed.3 In 1942 this problem was partially addressed by the KV-1S tank, which had thinner armor than the original, making it lighter and faster. It was competitive with the T-34 but at the cost of no longer having the heavier armor. Production of the KV-1S was gradually replaced by the SU-1524 and ended in April 1943.5 The capture of a German Tiger tank in January 1943 led to a decision to develop a new heavy tank, which was given the codename Object 237.6 Before Object 237 had time to mature, intense tank fighting in the summer of 1943 demanded a response. Dukhov's team was instructed to create a stopgap KV tank, the KV-85, which was armed with the 52-K-derivative gun of the SU-85, the 85 mm D-5T that proved capable of penetrating the Tiger I from 1,000 m (1,100 yd). The KV-85 was created by mounting an Object 237 turret on a modified KV-1S hull, by increasing the diameter of the turret ring with fillets on the sides of the hull. The radio operator was removed and in his place was inserted an ammunition rack for the larger 85 mm ammunition. The hull MG was then moved to the opposite side of the driver and fixed in place to be operated by the driver. Soviet industry was therefore able to produce a heavy tank as equally well armed as the Tiger I before the end of 1943. There was a short production run of 148 KV-85 tanks, which were sent to the front beginning in September 1943 with production ending by December.7 The complete Object 237 prototype, a version of the cancelled KV-13, was accepted for production as the IS-85 heavy tank.8First deliveries were made in October 1943 and the tanks went immediately into service. Production ended in January 1944. Its designation was simplified to IS-1 after the introduction of the IS-122, which was renamed as IS-2, for security purposes Gun: Through this period, further development of the T-34 was taking place and by 1943 engineers had succeeded in mounting the 85 mm gun to this chassis, making the IS-85 superfluous as the original T-34 had the KV-1. Efforts to up-gun the IS-85 began in late 1943. Two candidate weapons were the D-25 122 mm tank gun whose ballistic characteristics were identical to the A-19 122 mm gun,10 and the D-10 100 mm gun, based on a naval dual-purpose gun. The D-10 had been designed for anti-tank fire and had better armour penetration than the A-19, 185 mm compared to 160 mm but the smaller calibre meant it had a less useful high explosive round. Also, the D-10 was a relatively new weapon in short supply, while there was excess production capacity for the A-19 and its ammunition. Compared to the older F-34 76.2 mm tank gun, the D-25 delivered 5.37 times the muzzle energy, while it had similar accuracy to that of the 88 mm L/71 gun mounted on the Tiger Ausf B. After testing both guns on the IS-122 and IS-100 respectively, the former was selected as the main armament of the new tank, because of its availability and the effect of its large high-explosive shell against German fortifications. The D-25 used a separate shell and powder charge, resulting in a lower rate of fire and reduced ammunition capacity, both serious disadvantages in tank-to-tank engagements. The gun was very powerful and while its 122 mm armour-piercing shell had a lower muzzle velocity than similar late-issue German 75 mm L/70 and 88 mm L/71 guns, Soviet proving-ground tests claimed that the D-25 could penetrate the front armour of the German Panther tank at 2,500 metres (2,700 yd) while the D-10 could do so at a maximum range of 1,500 metres (1,600 yd).1011 It was therefore considered an adequate anti-tank gun. A Wa Pruef 1 Report dated 5 October 1944 has data on the penetration ranges of the 122 mm A-19 gun against a Panther tank angled at 30 degrees: this estimated that the A-19 gun was unable to penetrate the glacis plate of the Panther from any distance, could penetrate the lower glacis plate of the hull from 100 metres (110 yd), could penetrate the mantlet from 500 metres (550 yd) and could penetrate the front turret from 1,500 metres (1,600 yd).12 The Panther's 40–50 millimetres (1.6–2.0 in) thick side armour would have been exposed and vulnerable at such angle; the sides at 30 degrees are penetrable from over 3,500 metres (3,800 yd) according to the same Wa Pruef 1 report.12 Testing with captured Tiger Ausf Bs in Kubinka claimed that the 122 mm D-25T was capable of penetrating the Tiger Ausf B'sturret from 1,000–1,500 metres (1,100–1,600 yd) and the weld joint or edges of the front hull plates at ranges of 500–600 metres (550–660 yd).13 It was the large HE shell the gun fired which was its main asset, proving highly useful and destructive as an infantry-killer. The most recognizable disadvantage of the D-25T gun was its slow rate of fire due the massive size and weight of the shells, only one to one and a half rounds per minute could be fired, initially.14 After some modernizations and the additional semi-automatic drop breech over the previously manual screw, the rate of fire increased to 2–3 rounds per minute.14 According to Steven Zaloga, the increase amounted to 3–4 rounds per minute.15Another limitation imposed by the size of its ammunition in a relatively small vehicle was the ammunition stowage; only 28 rounds could be carried inside the tank, with a complement of 20 HE rounds and 8 AP rounds the norm. Production: The IS-122 prototype replaced the IS-85 and began mass production as the IS-2. The 85 mm guns could be reserved for the new T-34-85 medium tank and some of the IS-1s built were rearmed before leaving the factory and issued as IS-2s. The main production model was the IS-2, with the powerful A-19. It was slightly lighter and faster than the heaviest KV model 1942 tank, with thicker front armour and a much-improved turret design. The tank could carry thicker armour than the KV series, while remaining lighter, due to the better layout of the armour envelope. The KV's armour was less well-shaped and featured heavy armour even on the rear, while the IS series concentrated its armour at the front. The IS-2 was slightly lighter than the Panther, much lighter than the Tiger I and Tiger II and had a lower silhouette than both. Western observers tended to criticise Soviet tanks for their lack of finish and crude construction. The Soviets argued that it was warranted, considering the need for wartime expediency and the typically short battlefield life of their tanks.18 Early IS-2s can be identified by the 'stepped' front hull casting with its small, opening driver's visor. The early tanks lacked gun tube travel locks or anti-aircraft machine guns and had narrow mantlets. According to Steven Zaloga, the IS-219 and Tiger I could knock each other out in normal combat distances below 1,000 m (1,100 yd). At any range, the performance of each tank against each other was dependent on the crew and combat situation.20 In late 1944, the stepped hull front was replaced with an improved single casting of 120 mm thickness angled at 60 degrees. This new nose lacked the opening driver's visor. it is sometimes incorrectly referred to as the IS-2m, but that designation actually refers to a much later modernisation program from the 1950s. Other minor upgrades included the addition of a travel lock on the hull rear, wider mantlet and, on very late models, an anti-aircraft machine gun. In the mid-1950s, the remaining IS-2 tanks (mostly model 1944 variants) were upgraded to the IS-2M standard, which introduced fittings such as external fuel tanks on the rear hull (the basic IS-2 had these only on the hull sides), stowage bins on both sides of the hull and protective skirting along the top edges of the tracks. Operational History: The IS-2 tank first saw combat in early 1944. IS-2s were assigned to separate heavy tank regiments, normally of 21 tanks each.31 These regiments were used to reinforce the most important attack sectors during major offensive operations. Tactically, they were employed as breakthrough tanks. Their role was to support infantry in the assault, using their large guns to destroy bunkers, buildings, dug-in crew-served weapons, and other 'soft' targets. They were also capable of taking on any German AFVs if required. Once a breakthrough was achieved, lighter, more mobile T-34s would take over the exploitation. Tactically, the IS-2s were deployed with the elite Guards Heavy Tank Regiments, which acted on request wherever a strongpoint was encountered. It was able to destroy Panther and Tiger tanks, as well as fortifications with HE rounds. According to German tactical instructions, a Panther had to close to 600 m (660 yd) to guarantee penetration of the IS-2's frontal armour, while the IS-2 could penetrate the Panther at ranges of 1,000 m (1,100 yd).191 The hull armour of the Soviet IS-2 model 1943 would be defeated byTiger I between 100 and 300 m (0.062 and 0.186 mi) at the driver's front plate and nose.,32 while the IS-2's 122 mm gun could penetrate the Tiger's front armour from between 500 and 1,500 m (0.31 and 0.93 mi). Frontal view of an IS-3. The squat, solid-looking front profile and pike nose armour shape are highly distinctive. US Army Ordnance Museum, Aberdeen Maryland (2008) By the 1950s the emergence of the main battle tank concept—combining medium-tank mobility with the firepower and later armour of the heavy tank—had rendered heavy tanks obsolete in Soviet operational doctrine. In the late 1960s the remaining Soviet heavy tanks were transferred to Red Army reserve service and storage. The IS-2 Model 1944 remained in active service much longer in the armies of Cuba,China and North Korea. A regiment of Chinese IS-2s was available for use in the Korean War, but saw no service there. In-game Description: The IS-2 is the fist of any assault. Its powerful HE round means you can knock out bunkers without the infantry shedding blood. The IS-2 should engage in combat with the German Cats, where the T-34s may not do the job. However, if advancing without infantry support, the IS-2 can fall prey to the Panzerfausts.